Since c654b8a9cba6002aad1c01919e4928a79a4a6dcf, the NFS server has made use of ext4's i_version when available. However, the new i_version support is available only when the filesystem is mounted with the i_version mount option. And the change attribute is required for completely correct NFSv4 operation, which we'd prefer to offer by default! I recall having a conversation with Ted T'so about ways to do this without affecting non-NFS-exported filesystems: maybe by providing some sort of persistant flag on the superblock which the nfsd code could turn on automatically if desired? But first it would be useful to know whether there is in fact any disadvantage to just having the i_version on all the time. Jean Noel Cordenner did some tests a couple years ago: http://www.bullopensource.org/ext4/change_attribute/index.html and didn't find any significant difference. But I don't know if those results were convincing (I don't understand what we're looking for here); any suggestions for workloads that would exercise the worst cases? --b. -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
